MANURING ORCHARDS. 153 



many, and sometimes by those who should know better, that fruit 

 growing is quite simihir to growing trees ; that the question of 

 soil exhaustion is not a matter of very great importance, provided 

 the soil is well cultivated, and that all soils contain sufficient quan- 

 tities of the food elements to insure the relatively small available 

 supply required from year to year. 



It is admitted that on soils of good mechanical condition, well 

 drained and cultivated, wiiich are naturally adapted for fruit as 

 well as other crops, because well supplied with the essential con- 

 stituents, nitrogen, phosphoric acid, potash, and lime, the exhaus- 

 tion arising from the continuous removal of crops will not become 

 apparent for a long time, but it should be emphasized that it is 

 only upon soils which possess these characteristics that the growth 

 of fruit, even poor fruit, can be continued for any considerable 

 period without the application of manures. 



While we have abundant evidence of the need of manures for 

 orchards, derived from our knowledge of the fact that even virgin 

 soils possess, as a rule, a low rather than a high natural strength, 

 and are, therefore, incapable of furnishing for a long time a 

 sufficient amount of one or more constituents, I desire to present 

 further evidence, derived, first, from experiments conducted to 

 determine the relative needs of plant food by certain fruit crops, 

 and second, from such results of actual practice as I have been 

 able to collate. 



The only completed experiment in this line is reported by the 

 New Jersey Experiment Station on peaches.' This experiment 

 was begun in 1884, and the results fully reported in 1894, though 

 I shall only use the results secured up to 1894. 



The object of this field experiment was to study the compara- 

 tive effect of an annual supply of what was deemed a sufficient 

 quantity of the best forms of the three plant food elements, nitro- 

 gen, phosphoric acid, and potash, when used singly and in various 

 combinations ; and of large applications of barnyard manure. 

 The experiment included thirteen plots, each one-tenth of an acre 

 in area, and containing thirteen trees. Each of the fertilized 

 plots received an annual application of 150 pounds of nitrate of 

 soda, 350 pounds of bone-black superphosphate, or 150 pounds 

 of muriate of potash per acre, thus furnishing an equivalent of 24 



I Annual Reports New Jersey Experiment Station, 1884-1894. 



